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Comment:Use an OP_NotFound opcode to cancel futile IN operators early. The current implementation is suboptimal because it always runs teh OP_NotFound. This still needs to be enhanced to only do the OP_NotFound if no results have been seen on the current loop.
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SHA3-256: 87a9fc504f9a78caf7a7949cc7ada0a19d61bfab51bb49a00a1607194c116212
User & Date: drh 2018-06-05 15:16:25.289
Context
2018-06-05
20:45
Add the OP_IfNoHope and OP_SeekHit opcodes used to reduce the number of unnecessary sqlite3BtreeMovetoUnpacked() calls when checking for an early exit on IN-operator loops. Futher optimizations are likely possible here. (check-in: 6bf251af43 user: drh tags: multikey-opt-idea)
15:16
Use an OP_NotFound opcode to cancel futile IN operators early. The current implementation is suboptimal because it always runs teh OP_NotFound. This still needs to be enhanced to only do the OP_NotFound if no results have been seen on the current loop. (check-in: 87a9fc504f user: drh tags: multikey-opt-idea)
13:54
Merge trunk changes. (check-in: 047295c588 user: drh tags: multikey-opt-idea)
Changes
Side-by-Side Diff Ignore Whitespace Patch
Changes to src/where.c.
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      struct InLoop *pIn;
      int j;
      sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
      for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
        sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
        if( pIn->eEndLoopOp!=OP_Noop ){
          if( pIn->nPrefix ){
            sqlite3VdbeAddOp3(v, OP_Noop, pLevel->iIdxCur,
            sqlite3VdbeAddOp4Int(v, OP_NotFound, pLevel->iIdxCur,
                              sqlite3VdbeCurrentAddr(v)+2,
                              pIn->iBase, pIn->nPrefix);
            VdbeCoverage(v);
          }
          sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop);
          VdbeCoverage(v);
          VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen);
          VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen);
        }
        sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
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Changes to src/wherecode.c.
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            int iCol = aiMap ? aiMap[iMap++] : 0;
            pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut);
          }
          sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v);
          if( i==iEq ){
            pIn->iCur = iTab;
            pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;
            if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 ){
            pIn->iBase = iReg - i;
            pIn->nPrefix = i;
              pIn->iBase = iReg - i;
              pIn->nPrefix = i;
            }else{
              pIn->nPrefix = 0;
            }
          }else{
            pIn->eEndLoopOp = OP_Noop;
          }
          pIn++;
        }
      }
    }else{
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